Computing devices typically include firmware responsible for hardware initialization, low-level hardware management, and managing the boot process. The main platform firmware responsible for booting the computing device may be implemented according to the Unified Extensible Firmware Interface (“UEFI”) specification, which has several versions published by the Unified EFI Forum. The UEFI specification specifies an interface between the firmware of the computing device and the operating system of the computing device. In addition to performing traditional boot and initialization tasks, such drivers and applications may perform other tasks, such as diagnostic, maintenance, or management tasks.
Typical pre-boot firmware executes with all components of the computing device in a fully operational power state (e.g., the “D0” state) without an operating system present to perform active power management. Therefore, powering on a computing device into the firmware may cause a large initial surge in power usage. Thus, battery-powered computing devices typically require some threshold amount of residual charge to be stored in the battery before booting to avoid depleting the battery, destabilizing the system, and in some circumstances damaging the computing device. Before the battery is sufficiently charged to fully boot the computing device, many typical computing devices enter a low-charge mode with no usable capability for the user (e.g., by displaying a “charging” icon or other indicator).
Certain platform firmware—typically legacy BIOS systems—have included “instant on” environments that may be activated instead of booting into a main platform operating system. Those firmware environments were typically simple and optimized for quick boot times, and were thus more popular when typical platform operating systems had longer boot times. Those firmware environments were separate from and otherwise not controlled by the platform operating system.